DNA methylation profile of multiple genes involved in bladder cancer among Saudi population - A pilot study

Background: To identify bladder cancer specific methylated DNA sequences for the Saudi population in order to detect and predict bladder cancer progression. Methods: In this study, we analysed DNA methylation levels of 48 tumour suppressor genes loci in 24 bladder tissues (19 bladder cancer samples and 5 control samples taken from histologically normal bladders). DNA Methylation analysis was done using Human Tumour Suppressor Genes EpiTect Methyl II Complete PCR Array from Qiagen (TM). Results: We identified significant difference in DNA hypermethylation levels at APC, BRCA1, CDH1, CDH13, CDKN2A, DAPK1, ESR1, FHIT, MGMT, RASSF1, SOCS1, TIMP3, TP73, VHL, WIF1 between controls and cancerous samples. It was also observed that CADM1 and DKK3 were differentially methylated in non-muscle invasive versus muscle invasive bladder cancer samples. Additionally, DNA hypermethylation of ESR1 was notified as the novel tumour suppressor gene specific for the Saudi population in bladder cancer. Conclusion: Our findings suggest that these aberrant DNA methylation patterns in bladder cancer are disease and population specific and have a potential to develop as distinct DNA methylation-based biomarkers in future.